51results about "Broadcast communication aspects" patented technology

A system that blends a hybrid radio signal may provide reduced audio content skipping and may determine an audio correlation between analog and digital signal components in the hybrid radio signal before blending from the analog signal component to the digital signal component. The system may reduce volume level transitions during blending by adjustment of blend and cross-fade variables, as well as setting a hysteresis mode to prevent undesirable sequential jumping from digital mode back to analog mode. The system also may compensate for digital AM frequency quality issues by adjustment of a filter bandwidth when the receiver blends an AM signal from analog to digital mode.

A system for blending a hybrid radio signal provides reduced volume level transitions during blending from an analog component of the hybrid signal to the digital component by adjusting blend and cross-fade variables, as well as setting a hysteresis mode to prevent undesirable jumping from digital mode back to analog mode sequentially. The system also compensates for digital AM frequency quality issues by adjusting a filter bandwidth when the transceiver blends the AM signal from analog to digital mode.

Methods and systems for temporally aligning audio samples of a digital portion of a radio broadcast signal with audio samples of an analog portion of the radio broadcast signal are disclosed. The methods and systems comprise the steps of receiving a radio broadcast signal having an analog portion and a digital portion; separating the analog portion of the radio broadcast signal from the digital portion of the radio broadcast signal; producing a first plurality of audio samples representative of the analog portion of the radio broadcast signal; retrieving from a memory a stored first time interval corresponding to an approximate time for data representing a first sample of the digital portion to travel through a digital signal path in a receiver, wherein the digital signal path includes a digital demodulator; measuring a second time for data representing the first sample of the digital portion to travel from an input of the digital signal path to an input of the digital demodulator; generating a delay amount for delaying a second plurality of audio samples relative to the first plurality of audio samples such that the second plurality of audio samples is temporally aligned with the first plurality of audio samples by adding the first time to the second time; producing the second plurality of audio samples representative of the digital portion of the radio broadcast signal; delaying the second plurality of audio samples by the delay amount such that the second plurality of audio samples is temporally aligned to within a predetermined amount with the first plurality of audio samples; and digitally combining the first plurality of audio samples with the second plurality of audio samples to produce a combined audio output.

This invention provides a method of detecting time alignment of an analog audio signal and a digital audio signal in a hybrid radio system. The method comprises the steps of filtering the analog audio signal to produce a filtered analog audio signal, filtering the digital audio signal to produce a filtered digital audio signal, and using the filtered analog audio signal and the filtered digital audio signal to calculate a plurality of correlation coefficients, wherein the correlation coefficients are representative of time alignment between the analog audio signal and the digital audio signal. An apparatus for performing the method is also provided.

A method for rendering an alert message on a digital radio broadcast receiver is described. A digital radio broadcast signal is received at the digital radio broadcast receiver. Data corresponding to an alert message comprising type information for identifying a type of the alert message and message information is detected. If the type information satisfies a triggering condition for a type of alert message pre-selected by a user of the digital radio broadcast receiver, the message information is rendered at the digital radio broadcast receiver. A digital radio broadcast receiver that performs the method is also described.

In accordance with the principles of the present invention, in addition to conventional use of frequency division multiplexed upper and lower side bands, the spectral area occupied by the analog host will be utilized by applying a one-dimensional modulation, e.g., pulse amplitude modulation (PAM) as opposed to the conventional use of a two-dimensional modulation, e.g., quadrature amplitude modulation (QAM). Furthermore, the analog and digital information within the analog host bandwidth may be combined in quadrature to keep the signals orthogonal. Thus, should one side band under the analog carrier be deteriorated or obliterated by adjacent channel interference, the other side band under the analog carrier can still provide useful data and hence better digital audio codec performance. By transmitting one or two digital data streams asymmetrically with respect to the center frequency, particular digital side bands can be rendered useless as environmental conditions warrant (e.g., as they become detrimentally affected by adjacent channel interference), reducing bandwidth capacity but not affecting the quality of the received digital data transmitted in any of the remaining digital side band regions.

A receiver accepts a digital signal having an upper side digital signal located in a higher frequency range on a frequency axis than an analog signal, and a lower side digital signal located in a lower frequency range on the frequency axis than the analog signal. A BPF (15) allows the analog signal to pass therethrough and a BPF (16) allows the analog signal and the digital signal to pass therethrough. BPFs (18) and (19) accept the output of the BPF (16) and output the upper side digital signal and the lower side digital signal, respectively. A digital receive level determining unit (20) and a selection SW (17) select either of the outputs of the BPFs (15) and (16) according to the receive levels of the upper side digital signal and the lower side digital signal, and output the selected output as a selected signal. The receiver then demodulates this selected signal.

A system that blends a hybrid radio signal may provide reduced audio content skipping and may determine an audio correlation between analog and digital signal components in the hybrid radio signal before blending from the analog signal component to the digital signal component. The system may reduce volume level transitions during blending by adjustment of blend and cross-fade variables, as well as setting a hysteresis mode to prevent undesirable sequential jumping from digital mode back to analog mode. The system also may compensate for digital AM frequency quality issues by adjustment of a filter bandwidth when the receiver blends an AM signal from analog to digital mode.

An broadcasting receiver suitable for receiving a broadcasting signal transmitted in an IBOC signal format, includes: a narrowband filtering means suitable for processing an analog broadcasting signal included in the broadcasting signal; a wideband filtering means suitable for processing a digital broadcasting signal included in the broadcasting signal; a demodulating means for demodulating the broadcasting signal; a signal level detecting means for detecting a level of the broadcasting signal; a digital determining means for determining whether the broadcasting signal includes digital broadcasting signal or not; and a filter switching means for switching filtering means for use in processing the broadcasting signal to be input to the demodulating means between the narrowband filtering means and the wideband filtering means, according to the level of the detected broadcasting signal, when the digital determining means determines that the broadcasting signal does not include the digital broadcasting signal.

A method of processing a digital radio broadcast signal includes: (a) determining a plurality of current correlation sample values representative of a time delay between samples in an analog audio sample stream and samples in a digital audio sample stream; (b) determining a current inversion status; (c) updating a delay history and an inversion status history; (d) checking the current correlation sample values for consistency with a first confidence threshold; (e) if consistency is found in step (d), determining if each of a first plurality of values in the delay history is consistent within a predetermined range of the current correlation sample values; (f) if consistency is found in step (e), determining if a value in the inversion status history is consistent with the current inversion status; and (g) if the consistency is found in step (f), allowing blending of an output to the digital audio sample stream.

The present invention is directed to the provision of a radio receiver and of a radio receiving method that can reliably detect IBOC hybrid broadcast carrier waves. The radio receiver includes a tuning section for tuning to the frequency of a broadcast carrier wave, a detection section for detecting the signal level of the broadcast carrier wave at the frequency to which the tuning section has tuned, and a control section for detecting an IBOC hybrid broadcast carrier wave, based on a first signal level detected by the detection section by causing the tuning section to tune to a first frequency, a second signal level detected by the detection section by causing the tuning section to tune to a second frequency, and a third signal level detected by the detection section by causing the tuning section to tune to a third frequency. The radio receiving method is implemented in such a radio receiver.

A system and method for providing access to supplemental program services is provided. Generally, the system contains an antenna, a display, a control device, a memory, and a processor configured by the memory. The processor is configured by the memory to perform the steps of: sequentially arranging the audio programs received by the system in accordance with a representation of a carrier frequency, where the audio programs comprise at least one main program service and at least one supplemental program service, the main program service being located within the sequential arrangement at a location of a first carrier frequency at which the main program service was received, and the at least one supplemental program service received at the first carrier frequency being sequentially listed near the main program service; and displaying the sequentially arranged programs on the display so that the programs may be searched by use of the control device.

An FM broadcast transmitter transmits a broadcast signal having a carrier at a broadcast frequency and sidebands, able to be transmitted at full power, within a transmission band-width around the carrier. It includes a source of a modulated FM stereo signal having a carrier at the broadcast frequency and having sidebands with a bandwidth less than the transmission bandwidth representing a stereo signal. It also includes a source of a modulated IBOC signal, having carrier pulses spaced relative to each other to represent the IBOC digital data signal encoded as a variable pulse width encoded signal, and a bandwidth within the transmission bandwidth not overlapping the FM stereo signal sidebands. A signal combiner combines the modulated FM stereo signal and the modulated IBOC signal to form the broadcast signal. An FM broadcast receiver receives a broadcast signal including a first modulated signal representing an FM stereo signal, and a second modulated signal, having carrier pulses spaced relative to each other to represent an in-band-on-channel (IBOC) digital data signal encoded as a variable pulse width encoded signal. It includes a signal separator for generating a first separated signal representing the FM stereo signal and a second separated signal representing the IBOC digital data signal. An FM signal processor generates a stereo audio signal represented by the FM stereo signal. An IBOC signal processor generates a digital data signal represented by the IBOC digital data signal.

A method for carrier tracking in AM in-band on-channel radio receivers comprises the steps of receiving an input signal, generating a local oscillator signal in response to an oscillator control signal, mixing the input signal with a local oscillator signal to produce a first signal, filtering the first signal to produce a filtered first signal at a decimated sample rate, detecting the phase error and frequency error of the filtered first signal normalized to mitigate effects of signal fades, and using an adaptive loop filter to produce the oscillator control signal in response to the phase error and frequency error of the filtered first signal. An apparatus that performs the method is also provided.

An object of the present invention is to provide a radio receiver and a method for detecting carrier waves which make it possible to detect carrier waves for an IBOC type hybrid broadcast reliably. A radio receiver for receiving carrier waves for hybrid broadcasts which are arranged so as to be adjacent to and located on both sides of carrier waves for analog broadcasts in frequency bands includes a tuner for tuning to a broadcast frequency, and a controller for setting a center frequency of shift frequency in a range where carrier waves for an analog broadcast can be detected and allowing the tuner to tune to the set shift frequency.

The invention relates to an unmanned aerial vehicle management method based on frequency modulation data broadcast, an unmanned aerial vehicle, a monitoring terminal and a management center. The method comprises the following steps: receiving and demodulating a first frequency modulation data broadcast signal sent by the management center, wherein the first frequency modulation data broadcast signal comprises a frequency point information frame, and the frequency point information frame comprises available frequency point information; determining an own broadcast frequency point according to the available frequency point information; generating a flight state information frame according to the obtained own flight state information and a preset frequency modulation data broadcast information frame format; generating a second frequency modulation data broadcast signal according to the flight state information frame and the preset frequency modulation data broadcast information frame format; and broadcasting the second frequency modulation data broadcast signal on the own broadcast frequency point. By adoption of the unmanned aerial vehicle management method provided by the invention, the use of mobile communication network resources in the unmanned aerial vehicle management system is omitted, thereby reducing the flow cost of users.

The invention discloses a Zynq-based multichannel AM and FM demodulation method. The method comprises the following steps of command issuing and data collection, digital down conversion and AM demodulation or FM demodulation. Four demodulation channels are provided, and AM / FM modulation signals in four channels can be demodulated at the same time. As digital down conversion and signal demodulation which require a large amount of logic resources are put in an FPGA for operation, the FPGA has a parallel processing capability and provides special DSP resources, the demodulation data rate for the FPGA is theoretically only limited by the clock rate of the FPGA (Zynq can reach 300 MHz or above), and as the FPGA has the parallel processing capability, the signal precision (data bit width) is improved as much as possible when digital down conversion and demodulation are carried out, the FPGA operation speed is not influenced in a condition in which the resources are met, and real-time processing of multichannel signals can be met completely.

A broadcasting receiver suitable for receiving broadcasting signal transmitted with signal format is provided in which carrier wave is allocated in a frequency channel with certain frequency offset and signal intensity, which comprises: an information acquiring means for acquiring information related to the frequency channel in seek; and a station existence determining means for determining whether the frequency channel is station-existent or not based on information acquired by the information acquiring means; and wherein, the information acquiring means acquires information for receiving intensity of carrier wave and information for frequency offset.

A method for processing a radio signal includes: receiving an FM in-band on-channel radio signal including a plurality of digitally modulated subcarriers in upper and lower sidebands; sampling the FM in-band on-channel radio signal to produce an input signal including complex digital samples of a combination of a desired one the upper and lower sidebands and an FM interferer; removing FM interferer components from the first signal by notch filtering to produce a notch-filtered signal; weighting the notch-filtered signal to produce a weighted notch-filtered signal; using a parametric filter to filter the input signal to produce a parametric-filtered input signal; and combining the weighted notch-filtered signal and the parametric-filtered input signal to produce an output signal. A radio receiver that implements the method is also included.

A method and apparatus are disclosed for combining digital sidebands with an FM analog signal for IBOC transmission by a single antenna. Specifically, a high power filter combiner for combining an FM analog and a digital signal of the same channel, or frequency, is disclosed. The combiner has two inputs that respectively receive an FM analog and a digital signal to be transmitted in the same FM channel. The combiner has mild tuned filters interposed between the inputs and the output which are tuned to pass the FM analog signal while reflecting the digital signal such that the passed FM analog signal and the reflected digital signal combine as IBOC, i.e., an FM analog signal with digital sideband signals. The combined IBOC signal is provided at an output of the combiner, capable for transmission through a single antenna.

An apparatus includes a network receiver for receiving an over-the-air in-band on-channel broadcast signal and extracting broadcast content from the broadcast signal, and an output for delivering the content by way of a first receiver output signal to a plurality of network player devices. A method performed by the apparatus is also included.

A reception apparatus includes: a local oscillation section; first and second frequency mixing sections that mix received radio waves from AM and FM broadcast stations with an output signal from the local oscillation section to produce first and second intermediate frequency signals, respectively; an amplitude limiting section that limits an amplitude of the first or second intermediate frequency signal to a predetermined amplitude, and detects an intensity of the radio wave and a frequency offset from the signal; a multipath detecting section that extracts an amplitude change component in the signal amplitude-limited by the amplitude limiting section; and a control section that supplies a control signal for fixing the frequency to the local oscillation section when the intensity of the radio wave from the AM broadcast station and the frequency offset fulfill predetermined criteria, and when the amplitude change component is equal to or lower than a predetermined level.

A method and apparatus are disclosed for combining digital sidebands with an FM analog signal for IBOC transmission by a single antenna. Specifically, a high power filter combiner for combining an FM analog and a digital signal of the same channel, or frequency, is disclosed. The combiner has two inputs that respectively receive an FM analog and a digital signal to be transmitted in the same FM channel. The combiner has mild tuned filters interposed between the inputs and the output which are tuned to pass the FM analog signal while reflecting the digital signal such that the passed FM analog signal and the reflected digital signal combine as IBOC, i.e., an FM analog signal with digital sideband signals. The combined IBOC signal is provided at an output of the combiner, capable for transmission through a single antenna.

A method for optimising the transmission power of an FM radio broadcasting transmitter includessampling a signal representative of the audio content to be broadcasted by the FM radio broadcasting transmitter;continuously calculating the constituent parameters of the representative signal from frequency, amplitude, dynamic range, temporal distribution, energy and power;continuously analysing the parameters by comparison with a model of psycho-acoustic data;generating a controlling signal for controlling the power of the transmitter as a function of the results of the analysis and of the calculations allowed by the constituent parameters and the continuous psycho-acoustic data;driving of the RF power of the transmitter by means of the controlling signal.A device for implementing the method in an FM radio broadcasting transmitter is also proposed.